Preston chronicles human encounters with the Marburg and Ebola viruses, among the most lethal viruses known. He discusses the effects of the viruses on people infected with them, and suggests that they have emerged as the world's jungles and rain forests have been destroyed. He also describes outbreaks of the viruses, particularly an outbreak of a strain of Ebola among monkeys imported to the United States, and how the outbreak was contained. Strong language and explicit descriptions of violence. 1994.